The present invention relates to a helmet comprising retractable visors for fast day/night reconfiguration.
A helmet for an aircraft pilot, particularly the pilot of a combat airplane, is generally a multifunction affair equipped with visors. Such a helmet comprises a rigid shell which generally surrounds the top, rear and lateral parts of the wearer""s skull. The helmet generally comprises visors through which the helmet wearer can see his environment; these visors are usually retractable toward the top of the skull and afford the face protection against various kinds of attack (wind, dust, light or strong illumination, etc.). For that, a standard helmet is generally provided with a dark visor arranged closest to the face and retractable up inside the helmet, to afford protection against strong illumination, particularly for day vision. Furthermore, for day use, a retractable clear visor mounted on the shell of the helmet on the outside and lockable in a folded-down position is provided. For night use, it is necessary to insert night vision equipment in front of the wearer""s eyes. However, the bulk of such equipment then prevents it from being possible to lower the clear day visor.
One very important problem which arises with all helmets is that of the weight carried when the pilot has to eject or in the event of a violent impact (if the aircraft crashes for example. What happens during ejection is that it is absolutely essential for the pilot""s face to be protected by a fold-down visor. Furthermore, the weight of the functional elements added to the helmet and the way in which they are positioned tend to impose forces which are dangerous to the pilot""s neck in the event of strong accelerations, such as the acceleration involved in an ejection, and it is therefore necessary to avoid adding additional elements, particularly ones positioned away from the natural center of gravity of the pilot""s bare head and neck.
One solution currently recommended in the event of pilot ejection is for the night vision equipment to be ejected then the clear day visor lowered before the pilot ejects. However, a significant disadvantage is that the ejection of the pilot needs to be prepared for. It might be possible to anticipate keeping the night vision equipment with a third clear visor arranged in front of it to protect the pilot""s face in the event of ejection. That would allow for unprepared ejection. However, the mass added to the helmet and the offset of the center of gravity would then become prohibitive (5 to 10% would be added to the weight of the helmet with a significant lever arm with respect to the pilot""s neck).
The anticipated solution is therefore to provide just two visors (one clear, one dark) for use whether by day or by night.
For that, the invention anticipates adapting the standard helmet to allow fast reconfiguration replacing a day visor which does not adversely affect the ergonomics of the standard helmet, by a night module incorporating night vision equipment and a clear visor in front of this equipment and lockable in the down position. This is achieved according to the invention using articulations between the visor or the night module and the helmet that can be disassembled without tools.
According to the invention, there is therefore provided a helmet comprising retractable visors for fast day/night reconfiguration, said helmet comprising a shell including a saggital guide rail with a central opening, characterized in that it comprises a retractable day visor or a night module incorporating night vision equipment and a retractable visor in front of this equipment, the day visor and the night module being interchangeable rapidly and without tools and comprising an upper central part collaborating with said guide rail and lateral arms each symmetrically equipped with an articulation to the shell of the helmet that can be disassembled without tools and in that each of said articulations about a common rotation axis comprises a first part secured to the shell, comprising at least one guide boss for guidance in a predetermined direction perpendicular to said rotation axis and a peripheral channel and a second part secured to the arm comprising at least one locking lever articulated in said second part to be immobilized in said channel.
This easy removal is made possible by virtue of a special articulation architecture.
According to this other aspect of the invention, there is therefore provided a helmet as defined hereinabove, characterized in that:
said first part comprises a bearing and guide piece secured to the shell having at least one bearing face perpendicular to said axis which it surrounds and exhibiting said guide boss for guidance in said predetermined direction perpendicular to said rotation axis;
said second part comprises at least:
an intermediate piece consisting of a washer equipped with a peripheral groove and with a slot extending from the center to the periphery of the intermediate piece, the respective shape and size of said slot and of said boss being tailored to one another so that when the intermediate piece comes to bear against said bearing surface of the bearing piece, the boss is engaged in the slot and prevents the intermediate piece from rotating;
said lever of semicircular overall shape pivoting about a pivot arranged in the groove of the intermediate piece and on the opposite side to the opening of the slot, said boss comprising an outer peripheral channel which can be aligned with the groove of the intermediate piece when the latter is bearing against the bearing piece so that the internal edge of the lever, in the locked position, becomes inserted in the facing part of the groove and in the channel of the boss;
means of fixing the intermediate piece on said arm allowing these pieces a limited relative rotation about the rotation axis;
and in that said predetermined direction of each of the articulations lies in a plane containing said rotation axes and the center of the central opening of the rail.
By nature of these features it is thus possible quickly and without tools to reconfigure the helmet, switching from a day configuration with a clear day visor to a night configuration with a night module and lockable clear visor, in all cases allowing the pilot to eject without any preparation while at the same time maintaining common day use without any adverse effects on ergonomics.